Three-dimensional thermal sensitivity analysis of cooling of a magma chamber in the Los Azufres geothermal field, Michoacán, Mexico

Surendra P Verma,Efraín Gómez-Arias

doi:10.1186/2195-9706-1-5

Abstract

We present three-dimensional simulation of cooling of 63 models of a magma chamber in the Los Azufres geothermal field by varying the top of the chamber depth between 5 and 9 km (centroid from about 7 to 13 km) and its volume between 300 and 600 km3. Nineteen new best-fit cubic equations are presented to represent the temperature field in the geothermal reservoir in terms of the chamber centroid depth, its volume, or both. These equations clearly show that the thermal regime is much more sensitive to chamber depth than to its volume. These simulation results imply that, for a better estimation of the energy budget of a volcanic area, the depth parameter should be better constrained than the chamber volume. Geoscientists are, therefore, encouraged to obtain more reliable estimates of magma chamber depths for active volcanoes and potential geothermal areas. Furthermore, the smallest discretization time and mesh size should be used for solving the heat flow equations in three-dimensions.

Highlights

We present three-dimensional simulation of cooling of 63 models of a magma chamber in the Los Azufres geothermal field by varying the top of the chamber depth between 5 and 9 km and its volume between 300 and 600 km3
The sensitivity of two magma chamber parameters - chamber depth and volume was evaluated by Verma et al (2011) at the top of the magma chamber as well as at its sides, which indicated that the chamber depth is more sensitive than the chamber volume
We note that we have evaluated the thermal regime in terms of the centroid depth, the inference will not change had we used the top of the chamber depth, instead of the centroid depth

Summary

Introduction

We present three-dimensional simulation of cooling of 63 models of a magma chamber in the Los Azufres geothermal field by varying the top of the chamber depth between 5 and 9 km (centroid from about 7 to 13 km) and its volume between 300 and 600 km. Three-dimensional thermal modeling of a magma chamber has been already applied to decipher thermal regime beneath the Los Humeros and La Primavera geothermal fields, located in the eastern and western parts of the Mexican Volcanic Belt, respectively (LHGF and LPGF, respectively, in Figure 1; Verma and Andaverde 2007; Verma et al 2012; Verma and Gómez-Arias 2013a). Such a three-dimensional model has been put forth for cooling of two magma chambers in the Las Tres Vírgenes geothermal field, Baja California Sur, Mexico (Guerrero-Martínez and Verma 2013).

Methods

Results

Conclusion